| New Twist On 1930s Technology May Become a 21st Century Weapon Against Global Warming |
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Far from being a pipe dream years away from reality, practical technology for capturing carbon dioxide -- the main greenhouse gas -- from smokestacks is aiming for deployment at coal-fired electric power generating stations and other sources, scientists saidin San Diego March 27. Their presentation at the 243rd National Meeting of the American Chemical Society was on a potential advance toward dealing with the 30 billion tons of carbon dioxide released into the air each year through human activity.
"With little fanfare or publicity and a decade of hard work, we have made many improvements in this important new technology for carbon capture," said James H. Davis, Jr., Ph.D., who headed the research. "In 2002, we became the first research group to disclose discovery of the technology, and we have now positioned it as a viable means for carbon dioxide capture. Our research indicates that its capacity for carbon dioxide capture is greater than current technology, and the process is shaping up to be both more affordable and durable as well."
The new approach has a back-to-the-future glint, leveraging technology that the petroleum industry has used since the 1930s to remove carbon dioxide and other impurities from natural gas. Davis, who is with the University of South Alabama (USA) in Mobile, explained that despite its reputation as a clean fuel, natural gas is usually contaminated with a variety of undesirable materials, especially carbon dioxide and hydrogen sulfide. Natural gas from certain underground formations, so-called "sweet" gas, has only small amounts of these other gases, while "sour" gas has larger amounts. Natural gas companies traditionally have used a thick, colorless liquid called aqueous monoethanolamine (MEA) to remove that carbon dioxide.
Several problems, however, would prevent use of MEA to capture carbon dioxide on the massive basis envisioned in some proposed campaigns to slow global warming. These involve, for instance, capturing or "scrubbing" the carbon dioxide from smokestacks before it enters the atmosphere and socking it away permanently in underground storage chambers. Vast amounts of MEA would be needed, and its loss into the ... |
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| Transparent, Flexible '3-D' Memory Chips May Be the Next Big Thing in Small Memory Devices |
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New memory chips that are transparent, flexible enough to be folded like a sheet of paper, shrug off 1,000-degree Fahrenheit temperatures -- twice as hot as the max in a kitchen oven -- and survive other hostile conditions could usher in the development of next-generation flash-competitive memory for tomorrow's keychain drives, cell phones and computers, a scientist reported March 27.
Speaking at the 243rd National Meeting & Exposition of the American Chemical Society, the world's largest scientific society, he said devices with these chips could retain data despite an accidental trip through the drier -- or even a voyage to Mars. And with a unique 3-D internal architecture, the new chips could pack extra gigabytes of data while taking up less space.
"These new chips are really big for the electronics industry because they are now looking for replacements for flash memory," said James M. Tour, Ph.D., who led the research team. "These new memory chips have numerous advantages over the chips today that are workhorses for data storage in hundreds of millions of flash, or thumb drives, smart phones, computers and other products. Flash has about another six or seven years in which it can be built smaller, but then developers hit fundamental barriers."
Because of the way that the new memory chips are configured, namely with two terminals per bit of information rather than the standard three terminals per bit, they are much better suited for the next revolution in electronics -- 3-D memory -- than flash drives.
"In order to put more memory into a smaller area, you have to stack components beyond two dimensions, which is what is currently available," he said. "You have to go to 3-D." And the chips have a high on-off ratio, which is a measure of how much electrical current can flow in the chip when it stores information versus when it is empty. The higher the ratio, the more attractive the chips are to manufacturers.
The chips were originally composed of a layer of graphene or other carbon material on top of silicon oxide, which has long been considered an insulator, a passive component in electronic devices. Graphene is a thin layer of carbon atoms that's... |
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